Home About us MoEF Contact us Sitemap Tamil Website  
About Envis
Whats New
Microorganisms
Research on Microbes
Database
Bibliography
Publications
Library
E-Resources
Microbiology Experts
Events
Online Submission
Access Statistics

Site Visitors

blog tracking


 
Colloids and Surfaces B: Biointerfaces
Vol.
91, No. xx, 2011; Pages: 205 - 211

Influence of surface characteristics on biofouling formed on polymers exposed to coastal sea waters of India

K. Lakshmi, T. Muthukumar, M. Doble,L. Vedaprakash, Kruparathnam, R. Dineshram, K. Jayaraj, R. Venkatesan

Department of Biotechnology, Indian Institute of Technology Madras, Chennai 600036, India.

Abstract

Biofouling on six different (silicone rubber, polydimethylsiloxane, polypropylene, high density polyethylene, polyvinylchloride, and polycarbonate) substrata with varying surface energy (18–40 mN/m) and surface roughness (Ra 45–175 μm) was studied in the Eastern coastal waters of India over a short period of time (3 days). The results showed that the substrata surface energy (SE) followed by the surface roughness (Ra) had profound effect on attachment of fouling organisms. After one day of immersion, viable count of bacteria in the biofilm was positively correlated with surface energy (r = 0.69, p < 0.05) and not with surface roughness (r = −0.02) of the substratum. Whereas, Pseudomonas count was inversely correlated with surface energy (r = −0.66, p < 0.05) and surface roughness (r = −0.52, p < 0.05). The attachment of macrofouler and the surface characteristics were also well correlated with SE 0.48 and with roughness 0.62, p < 0.05. A positive correlation was observed amongst the various biofouling constituents such as bacteria, ATP, carbohydrates and organic matter on almost all the substrata. However after the first day, the surface characteristics of the substratum became less important and the conditioning film that was formed on the substrata appeared to directly influence further fouling on the surfaces, as evidenced by poor correlation between surface energy and macrofouler attachment (r = −0.11). The observation of high numbers of Hydroides elegans on PVC could be solely due to the influence of surface roughness (r = 0.62). Though there is no marked difference in the ‘primary film’, and the composition of the biofilm, the amount of attached macrofouler is minimal on silicone rubber and polydimethylsiloxane on subsequent days of immersion, which reveals the foul release quality of these substrata probably due to their flexible nature.

Keywords: Surface energy; Surface roughness; Polymeric substrata; Organic matter; Carbohydrates; ATP


 

 

 
Copyright © 2005 ENVIS Centre ! All rights reserved
This site is optimized for 1024 x 768 screen resolution